7264. Phentolamine

Nomenclature

CAS number: 50-60-2
3-[[(4,5-Dihydro-1H-imidazol-2-yl)methyl](4-methylphenyl)amino]phenol; 2-[N-(m-hydroxyphenyl)-p-toluidinomethyl]imidazoline; 2-(m-hydroxy-N-p-tolylanilinomethyl)-2-imidazoline; 2-(N′-p-tolyl-N′-m-hydroxyphenylaminomethyl)-2-imidazoline; C-7337.
C17H19N3O; mol wt 281.35.
C 72.57%, H 6.81%, N 14.94%, O 5.69%.

Description and references

α-Adrenergic blocker. Prepn: K. Miescher et al., US 2503059 (1950 to Ciba); E. Urech et al., Helv. Chim. Acta 33, 1386 (1950). Pharmacology and toxicity: R. Meier et al., Proc. Soc. Exp. Biol. Med. 71, 70 (1949). HPLC determn in biological samples: B. D. Kerger et al., Anal. Biochem. 170, 145 (1988). Diagnostic use: G. Spergel et al., J. Am. Med. Assoc. 211, 266 (1970). Review of pharmacology and therapeutic applications: L. Gould, C. V. R. Reddy, Am. Heart J. 92, 397-402 (1976). Clinical efficacy of combination with papaverine in impotence: A. Bechara et al., J. Urol. 157, 2132 (1997).

Chemical structure

Properties

Crystals, mp 174-175°.

Derivative

Hydrochloride.

Nomenclature

CAS number: 73-05-2
C17H19N3O.HCl; mol wt 317.81.
C 64.25%, H 6.34%, N 13.22%, O 5.03%, Cl 11.16%.

Properties

Bitter crystals, mp 239-240°. One gram dissolves in 50 ml water, in 70 ml alcohol. Very slightly sol in chloroform. Practically insol in acetone, ethyl acetate. pH of 1% aq soln 4.5-5.5. Aq solns cannot be stored. LD50 in rats (mg/kg): 75 i.v.; 275 s.c.; 1250 orally (Meier).

Derivative

Methanesulfonate.

Nomenclature

CAS number: 65-28-1
Phentolamine mesylate; Regitine (Novartis); Rogitine (Novartis).
C17H19N3O.CH3SO3H; mol wt 377.46.
C 57.28%, H 6.14%, N 11.13%, O 16.95%, S 8.49%.

Properties

Crystals, mp 177-181°. One gram dissolves in 50 ml water, 23 ml alcohol, 660 ml chloroform. pH of 1% aq soln 4.5-5.5. Aq solns cannot be stored.

Therapeutic Category

Antihypertensive in treatment of pheochromocytoma; diagnostic aid (pheochromocytoma). In treatment of male erectile dysfunction.

Keywords

Antihypertensive; Imidazole Derivatives; Antipheochromocytoma; Diagnostic Aid